|Publication number||US5541811 A|
|Application number||US 08/417,905|
|Publication date||Jul 30, 1996|
|Filing date||Apr 6, 1995|
|Priority date||Apr 11, 1994|
|Also published as||CA2185987A1, CN1146273A, DE69503231D1, DE69503231T2, EP0755619A1, EP0755619B1, WO1995028073A1|
|Publication number||08417905, 417905, US 5541811 A, US 5541811A, US-A-5541811, US5541811 A, US5541811A|
|Inventors||Bo U. E. Henningsson, Stig A. Arvidsson|
|Original Assignee||Telefonaktiebolaget Lm Ericsson|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (10), Non-Patent Citations (2), Referenced by (62), Classifications (24), Legal Events (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present invention relates to an arrangement for shielding and/or cooling electronic components mounted on a circuit board. The arrangement includes a generally planar shielding hood having downwardly extending side edges extending around the perimeter thereof and intended for enclosing the components, and a cooling element having a generally planar underside and cooling fins or flanges arranged on its upper side.
Present day IC-components are becoming more and more integrated and therewith more complex. Furthermore, clock frequencies and power generation constantly increase. Microprocessors are a typical case. Parameters such as heat generation and disturbance sensitivity increase with the increasing complexity of IC-components, necessitating the need to shield and cool said components. At present, there is no effective economic or technical solution which combines these requirements, which in reality contradict one another.
The importance of providing effective screening or shielding of IC-components is reflected among other things in the discussions in present day mass media concerning, for instance, how mobile telephones render diserviceable the electronics of motor vehicles, such as cars. There is therefore a pronounced need of a technically simple and economic shielding/cooling construction which will fullfil simultanoeusly the stringent requirements placed on both these facilities.
The object of the present invention is to solve the aforesaid problem at low costs, by providing an arrangement which can be used either to solely shield an electronic component or solely cool an electronic component or which can be used to both shield and cool an electronic component in a simple manner and at low cost. This object is achieved by means of an arrangement having the characteristic features set forth in the following claims.
The inventive arrangement functions on the principle that in addition to functioning as a shield, the shielding hood shall also conduct heat to a cooling element. The construction is extremely flexible, and enables the following combinations to be obtained with precisely the same elements: shielding and cooling, solely shielding or solely cooling.
When needing to both cool and shield an electronic component, the shielding hood is used as a cooling means and as a heat conducting means and is placed betwen the heat source, for instance an IC-circuit, and a cooling element. In order not to obtain an excessively large thermal transition resistance, the shielding hood and cooling element must have well-defined abutment surfaces with the heat source. This is achieved by configuring both the shielding hood and the cooling element in a manner appropriate to the purpose intended.
The primary characteristic feature of the invention resides in the ability to combine cooling and shielding.
An embodiment of the invention at present preferred includes significant characteristic features which will now be described in more detail with reference to the accompanying drawings.
FIG. 1 is a perspective view of the elements included in the inventive arrangement.
FIG. 2 is a sectional view showing the arrangement mounted over a component.
FIGS. 3 and 4 are respective perspective views of the arrangement when used solely for shielding and solely for cooling respectively.
FIG. 5 is an alternative embodiment of an arrangement which is effective for both shielding and cooling purposes.
FIG. 6 is an alternative embodiment of the cooling element in which the holder means are placed in grooves.
FIG. 1 illustrates in perspective those elements which are included in an inventive arrangement. The illustrated arrangement is intended for shielding and/or cooling a component 1, for instance an IC-component, mounted on a circuit board 2. The arrangement includes a generally planar shielding hood 3, a generally planar cooling element 4, fastener means 5 in the form of hook means 6 and holder means 7 respectively, and contact springs 8.
The shielding hood 3 is configured as a substantially rigid frame and has downwardly extending side edges 31 and the size of the hood is adapted to the size of the component 1, so that the component will be fully surrounded by the side edges. The hood 3 is secured to the board 2, by pressing the side edges 31 into contact springs 8 which are surface mounted on the board around the component 1. The side edges include nibs 33 which function to lock the hood firmly in the contact springs. The hood 3 is intended primarily for shielding the component, although it shall also be capable of functioning as a means for conducting heat to the cooling element 4 when the arrangement is also intended for cooling purposes. To this end, it is necessary for the surface of the hood 3 that abuts the component to be well defined, so that the thermal transition resistance will not be too large. Accordingly, the hood has the form of a relatively rigid frame having a thinner central part 32 which is joined to the frame and which can move in relation thereto. The thinner part 32 functions as a movable diaphragm which is pressed against the component 1 with the aid of the cooling element 4. This mobility of the diaphragm enables the height of the hood or cover in relation to the height of the component to be readily adapted so as to ensure that positive abutment is achieved with a small heat transition resistance between component and cooling element, as shown in the sectioned view of FIG. 2.
The heat emitting surface area of the cooling element 4 is enhanced with the aid of a plurality of cooling fins 41 disposed on the upper side of the element. In addition, the cooling element 4 has a well defined abutment surface corresponding to the shielding hood 3, so as to reduce the resistance to thermal transition or transfer. As shown in the sectioned view of FIG. 2, the underside of the cooling element 4 has a downwardly directed, flat outwardly projecting part 42 which may either lie against the central part, the diaphragm 32, of the hood 3 when both shielding and cooling are required, or directly against the component 1 when only cooling is required.
The cooling element 4 is held in place on the circuit board 2 with the aid of anchoring means 5 which in addition to providing a force which presses the cooling element, and the central part 32 of the hood, against the component also connects the cooling element 4 electrically to earth. In this regard, it is important that the cooling element is connected to earth at each corner. The fastener means 5 are comprised of hook means 6 mounted on the surface of the board 2, and holder means 7, mounted on the cooling element 4, which coact with respective hook means. Each hook means 6 has a generally U-shaped profile, whose one leg has the form of a solder pad 61, said solder pads being soldered to corresponding solder pads (not shown) on the board 2. Each other leg of the profile has the form of a hooked part 62, which is bent so as to be upstanding from the circuit board. The holder means 7 is made of a resilient material having a part 71 configured to enable said part to be clamped firmly between two cooling fins 41 on the cooling element, or, alternatively, in a specially configured groove, as shown in FIG. 6, provided on the cooling element, and a stepped second part 72 in which an opening 73 is provided and which can be brought into resilient or spring engagement with the hooked part 62 of the hook means 6, as illustrated in FIG. 2. A holder means 7 is placed in each corner of the cooling element, and a hook means 6 is placed in a corresponding position on the board 2. The spring effect thus obtained causes the cooling element 4 to be pressed into positive abutment with the shielding hood 3 and the component 1 respectively, which, as before mentioned, ensures good thermal contact between component and cooling element. The cooling element is, at the same time, positively earthed through the holding means 7 and the hook means 6, since anchoring means 5 are placed in each corner.
The above described arrangement is used when a component or components is/are to be shielded and cooled. When only shielding is required, only the shielding hood 3 will be used, as illustrated in FIG. 3. The hood is secured in contact springs 8 placed around the component 1 on the circuit board 2 and disposed so that the side edges 31 on the hood 3 will be inserted into the springs 8. This provides effective shielding of the component. The contact springs are also disposed so that the shielding hood 3 will be secured in the springs with the aid of the nibs 33, which are arranged on the sides of the hood in the manner indicated in FIG. 1. The contact spring 8, however, forms no part of the present invention.
When only cooling is required, the procedure is the same as that described above although in this case only the cooling element 4 is used, as illustrated in FIG. 4. The cooling element 4 is secured with the aid of four fastener means 5, in the same way as that described above.
There is sometimes a need to shield a group of components. This is made possible by the present invention, according to the embodiment shown in FIG. 5, in that the shielding hood 3 is provided in the central part or the diaphragm 32 with a plurality of openings 34 which form a defined hole pattern in the hood, as illustrated in FIG. 5. When requiring to cool a component, a cooling element 4 is placed over the component. The cooling element is affixed with the aid of four fasteners 5, wherein the hook means 6, and more specifically the hooked parts 62, extend up through the opening 34 in the shielding hood 3. In this way, it is possible to arrange one or more cooling elements 4 with associated fasteners 5 on the hood 3, above the component or components 1 that requires/require cooling.
It will be understood that the aforedescribed and illustrated embodiment is merely shown by way of example and that various alternative embodiments are conceivable. For instance the design of both the cooling element 4 and the fastener 5 and associated details can be varied in several ways without departing from the inventive concept.
Consequently, the invention is not restricted to the aforedescribed and illustrated embodiments thereof, since modifications can be made within the scope of the following claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4625260 *||Aug 24, 1984||Nov 25, 1986||Thermalloy Incorporated||Fasteners for surface mounting of printed circuit board components|
|US4758924 *||May 29, 1986||Jul 19, 1988||Honeywell Bull Inc.||Electronic equipment housing|
|US5237486 *||Jun 5, 1992||Aug 17, 1993||Apple Computer, Inc.||Structural frame for portable computer|
|US5253144 *||Aug 6, 1992||Oct 12, 1993||Siemens Aktiengesellschaft||Device housing having an integrated circuit board|
|US5295043 *||Feb 3, 1992||Mar 15, 1994||Tandon Corporation||Clip-on heat sink and method of cooling a computer chip package|
|US5357404 *||Nov 22, 1993||Oct 18, 1994||The Whitaker Corporation||EMI shield, and assembly using same|
|*||DE3737009A||Title not available|
|EP0380740A2 *||Jul 1, 1989||Aug 8, 1990||VDO Adolf Schindling AG||Electronical circuit|
|JPH03177095A *||Title not available|
|JPH06112674A *||Title not available|
|1||IBM Tech Discl. Bulletin "PIN-In-Heat Sink Attachment", vol. 33, No. 3, Aug. 1990, pp. 447-448, 257/718.|
|2||*||IBM Tech Discl. Bulletin PIN In Heat Sink Attachment , vol. 33, No. 3, Aug. 1990, pp. 447 448, 257/718.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US5603374 *||Apr 5, 1996||Feb 18, 1997||Malico Inc.||Heat sink assembly for an integrated circuit|
|US5668348 *||Oct 2, 1995||Sep 16, 1997||Lin; Chun-Sheng||CPU dissipator mounting apparatus|
|US5699229 *||Mar 28, 1996||Dec 16, 1997||Intel Corporation||Compliant hinge clip attachment|
|US5710694 *||Apr 30, 1996||Jan 20, 1998||Evercool Technology Co., Ltd.||Adjustable radiation fin fastening device for an integrated circuit chip|
|US5761041 *||Jun 25, 1996||Jun 2, 1998||Sun Microsystems, Inc.||Mechanical heat sink attachment|
|US5818695 *||Feb 25, 1997||Oct 6, 1998||Apple Computer, Inc.||Heat sink and spring clip assembly|
|US5891755 *||Mar 27, 1997||Apr 6, 1999||International Business Machines Corporation||Process for flat plate cooling a semiconductor chip using a thermal paste retainer|
|US5956925 *||Dec 31, 1997||Sep 28, 1999||Bmi, Inc.||Carrier tape and method for washing of components in carrier tape|
|US6043983 *||Jun 17, 1998||Mar 28, 2000||Intel Corporation||EMI containment for microprocessor core mounted on a card using surface mounted clips|
|US6049469 *||Aug 20, 1997||Apr 11, 2000||Dell Usa, L.P.||Combination electromagnetic shield and heat spreader|
|US6071128 *||Apr 28, 1998||Jun 6, 2000||International Business Machines Corporation||Integrated circuit socket with built in EMC grounding for a heat sink|
|US6075700 *||Feb 2, 1999||Jun 13, 2000||Compaq Computer Corporation||Method and system for controlling radio frequency radiation in microelectronic packages using heat dissipation structures|
|US6208516 *||May 11, 1999||Mar 27, 2001||Apple Computer, Inc.||Electromagnetic interference shield and gap filler for a circuit board|
|US6208517 *||Sep 10, 1999||Mar 27, 2001||Legerity, Inc.||Heat sink|
|US6239973 *||Mar 27, 2000||May 29, 2001||Intel Corporation||EMI containment for microprocessor core mounted on a card using surface mounted clips|
|US6243265 *||Oct 6, 1999||Jun 5, 2001||Intel Corporation||Processor EMI shielding|
|US6246584 *||Apr 16, 1999||Jun 12, 2001||Hon Hai Precision Ind. Co., Ltd.||Heat sink|
|US6273185 *||Dec 29, 1999||Aug 14, 2001||Foxconn Precision Components Co., Ltd.||Heat sink and retainer for electronic integrated devices|
|US6282095 *||Apr 27, 2000||Aug 28, 2001||Compaq Computer Corporation||Method and system for controlling radio frequency radiation in microelectronic packages using heat dissipation structures|
|US6445583 *||Jan 26, 2001||Sep 3, 2002||Laird Technologies, Inc.||Snap in heat sink shielding lid|
|US6583987 *||Apr 16, 2002||Jun 24, 2003||Intel Corporation||Electromagnetic interference and heatsinking|
|US6606246 *||Sep 21, 2001||Aug 12, 2003||Intel Corporation||Method and apparatus for retaining cooling apparatus and bus bar|
|US6723917 *||May 12, 2003||Apr 20, 2004||Gainward Co., Ltd.||Protective shield for against damaging circuit board and for safeguarding chip|
|US6757171||Oct 11, 2002||Jun 29, 2004||Infineon Technologies Ag||Device for fixing a heat distribution covering on a printed circuit board with heat distribution covering|
|US6958913 *||Nov 19, 2002||Oct 25, 2005||Samsung Electronics Co., Ltd.||Heatsink mounting unit|
|US7055589 *||Apr 30, 2003||Jun 6, 2006||Hon Hai Precision Ind. Co., Ltd.||Clip for heat sink|
|US7245896 *||Jun 23, 2003||Jul 17, 2007||Lg Electronics Inc.||Apparatus for improving reception sensitivity of public wave receiver by reducing noise externally-emitted in the public wave receiver|
|US7262369||May 10, 2006||Aug 28, 2007||Laird Technologies, Inc.||Combined board level EMI shielding and thermal management|
|US7317618 *||May 1, 2006||Jan 8, 2008||Laird Technologies, Inc.||Combined board level shielding and thermal management|
|US7400507 *||Oct 19, 2005||Jul 15, 2008||Inventec Corporation||Fastening structure|
|US7436673 *||Nov 30, 2006||Oct 14, 2008||Inventec Corporation||Heat sink fixing assembly|
|US7463496||May 1, 2006||Dec 9, 2008||Laird Technologies, Inc.||Low-profile board level EMI shielding and thermal management apparatus and spring clips for use therewith|
|US7623360||May 25, 2006||Nov 24, 2009||Laird Technologies, Inc.||EMI shielding and thermal management assemblies including frames and covers with multi-position latching|
|US7924568 *||Jun 29, 2009||Apr 12, 2011||Hon Hai Precision Industry Co., Ltd.||Heat sink device with a shielding member|
|US7965514||Jun 5, 2009||Jun 21, 2011||Laird Technologies, Inc.||Assemblies and methods for dissipating heat from handheld electronic devices|
|US8213180 *||Jun 30, 2010||Jul 3, 2012||Broadcom Corporation||Electromagnetic interference shield with integrated heat sink|
|US8477499||Jun 20, 2011||Jul 2, 2013||Laird Technologies, Inc.||Assemblies and methods for dissipating heat from handheld electronic devices|
|US8891241 *||Sep 14, 2012||Nov 18, 2014||Tatung Company||Electronic assembly|
|US9048124 *||Sep 20, 2012||Jun 2, 2015||Apple Inc.||Heat sinking and electromagnetic shielding structures|
|US9258928||Jun 3, 2013||Feb 9, 2016||Laird Technologies, Inc.||Assemblies and methods for dissipating heat from handheld electronic devices|
|US20030067754 *||Oct 11, 2002||Apr 10, 2003||Monika Bauer||Device for fixing a heat distribution covering on a printed circuit board and circuit board with heat distribution covering|
|US20030192672 *||Apr 30, 2003||Oct 16, 2003||Lee Hsieh Kun||Clip for heat sink|
|US20030235037 *||Nov 19, 2002||Dec 25, 2003||Samsung Electronics Co., Ltd.||Heatsink mounting unit|
|US20040014508 *||Jun 23, 2003||Jan 22, 2004||Seo Dong Han||Apparatus for improving reception sensitivity of public wave receiver|
|US20070086169 *||Oct 19, 2005||Apr 19, 2007||Inventec Corporation||Fastening structure|
|US20070209833 *||May 10, 2006||Sep 13, 2007||English Gerald R||Combined board level emi shielding and thermal management|
|US20070210082 *||May 25, 2006||Sep 13, 2007||English Gerald R||EMI shielding and thermal management assemblies including frames and covers with multi-position latching|
|US20070211436 *||May 1, 2006||Sep 13, 2007||Robinson Kenneth M||Combined board level shielding and thermal management|
|US20070211445 *||May 1, 2006||Sep 13, 2007||Robinson Kenneth M||Low-profile board level EMI shielding and thermal management apparatus and spring clips for use therewith|
|US20080130240 *||Nov 30, 2006||Jun 5, 2008||Inventec Corporation||Fixing structure of heat conduction pad|
|US20080266806 *||Apr 27, 2007||Oct 30, 2008||Lakin Eric D||Electronic assembly that includes a heat sink which cools multiple electronic components|
|US20080266807 *||Apr 27, 2007||Oct 30, 2008||Cray Inc.||Electronic assembly with emi shielding heat sink|
|US20100142153 *||Jun 29, 2009||Jun 10, 2010||Hon Hai Precision Industry Co., Ltd.||Heat sink device with a shielding member|
|US20110176279 *||Jun 30, 2010||Jul 21, 2011||Broadcom Corporation||Electromagnetic interference shield with integrated heat sink|
|US20130176683 *||Sep 14, 2012||Jul 11, 2013||Tatung Company||Electronic assembly|
|US20130340987 *||Jun 21, 2012||Dec 26, 2013||Asia Vital Components Co., Ltd.||Heat-dissipating base|
|US20140078677 *||Sep 20, 2012||Mar 20, 2014||Dominic E. Dolci||Heat Sinking and Electromagnetic Shielding Structures|
|US20150282388 *||Oct 17, 2013||Oct 1, 2015||Joseph Lee Carpenter||Heat sink attachment apparatus and method|
|WO2001078142A1 *||Apr 10, 2001||Oct 18, 2001||Infineon Technologies Ag||Device for fixing a heat distribution cover on a printed circuit board|
|WO2002041679A2 *||Nov 15, 2001||May 23, 2002||Laird Technologies, Inc.||Electromagnetic shielding and cooling device for printed circuit board|
|WO2002041679A3 *||Nov 15, 2001||Aug 29, 2002||Laird Technologies Inc||Electromagnetic shielding and cooling device for printed circuit board|
|WO2016018544A1 *||Jun 26, 2015||Feb 4, 2016||Thomson Licensing||Heatsink push pin ground/attachment method|
|U.S. Classification||361/704, 165/185, 174/16.3, 257/E23.114, 174/DIG.35, 165/80.2, 361/818, 257/E23.086, 257/719, 361/720, 174/377|
|International Classification||H05K7/20, H01L23/552, H01L23/40, H05K9/00, H01L23/58|
|Cooperative Classification||Y10S174/35, H01L23/4093, H01L23/585, H01L23/552, H01L2924/0002|
|European Classification||H01L23/58B, H01L23/552, H01L23/40S|
|Jul 6, 1995||AS||Assignment|
Owner name: TELEFONAKTIEBOLAGET LM ERICSSON, SWEDEN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HENNINGSSON, BO U.E.;ARVIDSSON, STIG A.;REEL/FRAME:007545/0676
Effective date: 19950615
|Jan 28, 2000||FPAY||Fee payment|
Year of fee payment: 4
|Jan 30, 2004||FPAY||Fee payment|
Year of fee payment: 8
|Jan 30, 2008||FPAY||Fee payment|
Year of fee payment: 12
|Feb 4, 2008||REMI||Maintenance fee reminder mailed|